Understanding the Practice of Decomposing Requirements into Failing Tests

In software development, breaking down requirements into tests that initially fail is a common practice. This method ensures that the code is developed to meet specific criteria, with tests guiding the implementation process.

Exam Question

The practice of decomposing a requirement into failing tests is called:
(choose the best answer)
A. Object oriented requirements definition.
B. Regression testing.
C. Behavior Driven Development.
D. Acceptance Test Driven Development.

Correct Answer

C. Behavior Driven Development.

Explanation

Correct Answer

C. Behavior Driven Development:
Behavior Driven Development (BDD) is a software development approach that involves writing tests in a way that describes the behavior of the system. These tests are initially failing because the functionality they describe has not yet been implemented. The development process involves writing just enough code to pass these tests. BDD encourages collaboration between developers, testers, and business stakeholders to create a shared understanding of the system’s behavior. This practice ensures that the development is aligned with business goals and that the system behaves as expected.

Why the Other Options Are Less Appropriate

A. Object oriented requirements definition:
This refers to defining requirements within an object-oriented framework, focusing on classes and their interactions. It does not involve the practice of using failing tests to guide development.

B. Regression testing:
Regression testing is the process of re-running tests after changes to ensure that existing functionality is not broken. It does not involve writing tests first to define system behavior.

D. Acceptance Test Driven Development:
While similar to BDD, Acceptance Test Driven Development (ATDD) focuses on writing acceptance tests based on requirements, which are then used to guide development. However, BDD specifically emphasizes the behavior of the system and involves collaboration with non-technical stakeholders.

Relevance to the PSD Exam

Understanding Behavior Driven Development is crucial for the PSD exam as it highlights the importance of aligning development with business needs and ensuring that the system behaves as expected.

Key Takeaways

• Behavior Driven Development involves writing failing tests that describe the desired behavior of the system.
• BDD encourages collaboration between developers, testers, and business stakeholders to ensure that the system meets its intended goals.

Conclusion

Behavior Driven Development is a valuable practice in software development that ensures that the system behaves as expected and meets business goals. By decomposing requirements into failing tests, teams can guide their development efforts effectively. For more information on preparing for the PSD exam, visit our Professional Scrum Developer PSD™ Exam Prep.